Radiation-induced lumbosacral plexopathy and pelvic insufficiency fracture: A case report of unique coexistence of complications after radiotherapy for prostate cancer.

Case reports of plexopathy after prostate cancer are usually neoplastic. Radiation-induced lumbosacral plexopathy and insufficiency fractures have clinical significance due to the need to differentiate them from tumoral invasions, metastases, and spinal pathologies. Certain nuances, including clinical presentation and screening methods, help distinguish radiation-induced plexopathy from tumoral plexopathy. This case report highlights the coexistence of these two rare clinical conditions. Herein, we present a 78-year-old male with a history of radiotherapy for prostate cancer who developed right foot drop, severe lower back and right groin pain, difficulty in standing up and walking, and tingling in both legs over the past month during remission. The diagnosis of lumbosacral plexopathy and pelvic insufficiency fracture was made based on magnetic resonance imaging, positron emission tomography, and electroneuromyography. The patient received conservative symptomatic treatment and was discharged with the use of a cane for mobility. Radiation-induced lumbosacral plexopathy following prostate cancer should be kept in mind in patients with neurological disorders of the lower limbs. Pelvic insufficiency fracture should also be considered if the pain does not correspond to the clinical findings of plexopathy. These two pathologies, which can be challenging to diagnose, may require surgical or complex management approaches. However, in this patient, conservative therapies led to an improvement in quality of life and a reduction in the burden of illness.

[Radiation-induced lumbosacral plexopathy with severe burning pain after 17 years of radiation therapy for cervical cancer: a case report].

A 73-year-old woman was admitted with severe burning pain, hyperesthesia, and weakness in the right lower extremity. The patient had undergone radio- and chemotherapy after surgery for cervical cancer 17 years earlier. We diagnosed radiation-induced lumbosacral plexopathy because of conduction block in the deep peroneal nerve and myokymic discharge in the tibialis anterior muscle. Pelvic computed tomography and magnetic resonance imaging ruled out recurrent tumor and nerve-compressing lesions. Although radiation-induced lumbosacral plexopathy is usually characterized by lower motor neuron syndrome, we report a rare case presenting with severe pain and hyperesthesia.

Dose delivered to the lumbosacral plexus from high-dose-rate brachytherapy for cervical cancer.

OBJECTIVE: To calculate dose delivered to the lumbosacral plexus (LSP) with cervical brachytherapy using 3-dimensional imaging, and to compare this with the position of the tandem in the pelvis using bony landmarks. We also report long-term LSP toxicity outcomes. METHODS AND MATERIALS: Treatment planning images from 55 patients treated with tandem and ring brachytherapy from October 2009 through November 2012 were reviewed. The LSP was contoured on planning computed tomographic scans to calculate dose received. Lumbosacral plexus dose was studied as a function of tandem distance from the sacrum and pubic symphysis (STratio) measured on digitally reconstructed radiographs. Patient and implant characteristics were included as covariates on LSP dose. Clinical follow up on LSP toxicity was recorded. RESULTS: Patients were prescribed 550 to 700 cGy using computed tomography-based imaged-guided brachytherapy for 4 to 5 fractions. The maximum dose to 2 cc (D2cc) of LSP ranged from 44 to 287 cGy per implant. The median D2cc was 118 cGy, corresponding to 18% of prescription dose. Patients with an STratio less than 0.33 (closer to the sacrum) and at least 0.33 had median LSP doses of 138 and 98 cGy, respectively. Lumbosacral plexus dose did not change significantly with body mass index, uterus position, or tumor stage. Two patients reported symptoms of peripheral neuropathy, with a median follow-up of 14.7 months. CONCLUSIONS: The mean D2cc per fraction to the LSP is roughly 20% of the prescribed high dose-rate and varies with the position of the tandem from the sacrum. The dose threshold for radiation-induced neuropathy of the LSP remains undefined.

External validation of the lumbosacral plexus-contouring protocol developed by Yi et al. (IJROBP 2012; 84: 376-82) for pelvic malignancies.

PURPOSE: To evaluate interobserver variability in contouring lumbosacral plexuses (LSP) using the protocol developed by Yi et al. (IJROBP 2012; 84: 376-82) and to review LSP dosimetries for conventional radiotherapy and intensity-modulated radiotherapy (IMRT) for pelvic cancers. METHODS AND MATERIALS: Using the above-mentioned protocol, seven outliners independently contoured LSPs of 10 consecutive patients (five patients treated with conventional radiotherapy and five with IMRT). Interobserver variability was reviewed visually by using planning axial CT images and anteroposterior digitally reconstructed radiographs. Dosimetries of LSPs were also calculated and compared. RESULTS: There was a notable learning curve for each outliner; duration to outline the first patient was 45-185 minutes, versus 15-50 minutes after six patients. We found significant interobserver variability among outliners below the level of the S2 nerve roots. The LSP volumes (mean volume range of 40.9-58.4 cc) were smaller than those described in the atlas paper (71-138 cc). The mean values of mean dose, maximum dose, V40 Gy, V50 Gy and V55 Gy, respectively, for patients treated with conventional radiotherapy versus those treated with IMRT were 35.5 Gy versus 33.6 Gy, 52.2 Gy versus 52.2 Gy, 61.3% versus 54.4%, 14.9% versus 18.8% and 0% versus 2.5%. CONCLUSION: We conclude that the protocol developed by Yi et al. is a useful set of guidelines but suggest that additional at-risk components of the LSP also be contoured. We recommend that radiation oncologists practise 'nerve-sparing' radiotherapy by contouring LSPs, especially when using IMRT. We propose the term 'lumbosacral plexus regions' (LSPRs) to highlight the fact that LSPs are not always radiologically visible, only the regions where they are likely to be present.

Development of a standardized method for contouring the lumbosacral plexus: a preliminary dosimetric analysis of this organ at risk among 15 patients treated with intensity-modulated radiotherapy for lower gastrointestinal cancers and the incidence of radiation-induced lumbosacral plexopathy.

PURPOSE: To generate a reproducible step-wise guideline for the delineation of the lumbosacral plexus (LSP) on axial computed tomography (CT) planning images and to provide a preliminary dosimetric analysis on 15 representative patients with rectal or anal cancers treated with an intensity-modulated radiotherapy (IMRT) technique. METHODS AND MATERIALS: A standardized method for contouring the LSP on axial CT images was devised. The LSP was referenced to identifiable anatomic structures from the L4-5 interspace to the level of the sciatic nerve. It was then contoured retrospectively on 15 patients treated with IMRT for rectal or anal cancer. No dose limitations were placed on this organ at risk during initial treatment planning. Dosimetric parameters were evaluated. The incidence of radiation-induced lumbosacral plexopathy (RILSP) was calculated. RESULTS: Total prescribed dose to 95% of the planned target volume ranged from 50.4 to 59.4 Gy (median 54 Gy). The mean (± standard deviation [SD]) LSP volume for the 15 patients was 100 ± 22 cm(3) (range, 71-138 cm(3)). The mean maximal dose to the LSP was 52.6 ± 3.9 Gy (range, 44.5-58.6 Gy). The mean irradiated volumes of the LSP were V40Gy = 58% ± 19%, V50Gy = 22% ± 23%, and V55Gy = 0.5% ± 0.9%. One patient (7%) was found to have developed RILSP at 13 months after treatment. CONCLUSIONS: The true incidence of RILSP in the literature is likely underreported and is not a toxicity commonly assessed by radiation oncologists. In our analysis the LSP commonly received doses approaching the prescribed target dose, and 1 patient developed RILSP. Identification of the LSP during IMRT planning may reduce RILSP. We have provided a reproducible method for delineation of the LSP on CT images and a preliminary dosimetric analysis for potential future dose constraints.

[Normal tissue tolerance to external beam radiation therapy: peripheral nerves]. / Dose de tolérance à l'irradiation des tissus sains: les nerfs périphériques.

Plexopathies and peripheral neuropathies appear progressively and with several years delay after radiotherapy. These lesions are observed principally after three clinical situations: supraclavicular and axillar irradiations for breast cancer, pelvic irradiations for various pathologies and limb irradiations for soft tissue sarcomas. Peripheral nerves and plexus (brachial and lumbosacral) are described as serial structures and are supposed to receive less than a given maximum dose linked to the occurrence of late injury. Literature data, mostly ancient, define the maximum tolerable dose to a threshold of 60 Gy and highlight also a great influence of fractionation and high fraction doses. For peripheral nerves, most frequent late effects are pain with significant differences of occurrence between 50 and 60 Gy. At last, associated pathologies (diabetes, vascular pathology, neuropathy...) and associated treatments have probably to be taken into account as additional factors, which may increase the risk of these late radiation complications.

[Radiation myelopathy and plexopathy].

Radiation myelopathy (RM) is a relatively rare disorder characterized by white matter lesions of the spinal cord resulting from irradiation. It is divided into two forms by the latent periods: transient RM and delayed RM. The delayed RM develops usually non-transverse myelopathy symptoms such as dissociated sensory disturbance, unilateral leg weakness, and gait disturbance with asymmetric steps. Spinal MRI shows initially cord swelling and long T1/T2 intramedullary lesion with enhancement, then exhibits cord atrophy. Histopathological findings of delayed RM are white matter necrosis, demyelination, venous wall thickening and hyalinization. Glial theory and vascular hypothesis have been proposed to explain its pathophysiology. Several therapies such as adrenocorticosteroid, anticoagulation and hyperbaric oxygen have been tried to this disease with variable benefits. Radiation plexopathy is classified into two major types by the location: radiation-induced brachial plexopathy (BP) and radiation-induced lumbosacral plexopathy (LSP). The BP initially emerges as arm and shoulder pain, whereas LSP as leg weakness. Myokymia and fasciculations are observed in both types. Electrophysiological study reveals findings of peripheral neuropathy. It is often difficult to distinguish the radiation plexopathy from cancer invasion to the plexus, but MRI is useful to differentiate between these diseases. Pathological findings are small vessel obstruction, thick fibrosis, axonal degeneration and demyelination. Its pathomechanism is presumed that radiation-induced fibrous tissue compresses the nerve root as well as microvascular obstruction of the nerve. Adrenocorticosteroid and anticoagulation are considered as the strategy for symptomatic relief.

Sacrolumbar intersegmental reflex circuit in men and its relation to the ejaculatory process.

OBJECTIVE: We aimed to investigate electrophysiologically the intersegmental reflex circuit from sacral to lumbar cord segments in normopotent adult men, in patients with spinal cord injury and in patients with premature ejaculation. METHODS: Reflex EMG activity of the cremasteric (CM) and bulbocavernosus (BC) muscles was recorded simultaneously by needle electrodes during electrical stimulation of the upper lumbar and sacral dermatomes, respectively. Thirty-three healthy male volunteers, 16 patients with spinal cord injury (SCI) at the thoracic or cervical levels, and 26 men with premature ejaculation (PME) were included in the study. RESULTS: In controls, upper lumbar dermatomal stimulation (ULS) at the inner side of thigh only elicited a reflex response from the CM muscle and did not produce a regular response from the lower sacral myotomes such as in the BC muscle. However lower sacral dermatomal stimulation (LSS) at the dorsal nerve of penis consistently evoked reflex responses from both CM and BC muscles. These basic electrophysiological features were not different in patients with SCI. LSS did not elicit a reflex response from the CM muscle in about 39% of patients with PME, while the BC reflex was obtained from all patients with PME. CONCLUSIONS: The neurophysiological pattern in BC and CM muscles during sacral or lumbar dermatomal stimulation reflects the sacrolumbar intersegmental reflex linkage that may be related to the ejaculatory process in men. The intersegmental sacrolumbar reflex circuit may be functionally disturbed in some patients with PME. SIGNIFICANCE: Interaction between the reflex activity of sacral to lumbar dermatomes could prove useful in defining electrophysiological mechanisms related to ejaculation in men.

Acupuncture stimulation to the sacral segment affects state of vigilance in rats.

The effects of acupuncture stimulation to the sacral segment on electroencephalograms (EEGs) and activity of locus coeruleus (LC) neurons were examined in urethane-anesthetized rats. In 71 of 112 trials, when EEGs displayed small amplitude and high frequency, stimulation to the sacral segment-induced large amplitude and slow EEGs with a latency of <450s and duration ranged from 32s to >42 min. Stimulus-induced EEGs comprised significant increases in delta power and significant decreases in theta and beta powers. After intraperitoneal administration of bicuculline, stimulation to the sacral segment failed to induce changes in EEG pattern. Firing rate of noradrenergic LC neurons decreased significantly from 2.9+/-1.5 to 1.1+/-0.8 Hz (n=11, p<0.001). Decreased neuronal activity exhibited close relationships with increased EEG amplitude. These results suggest that acupuncture stimulation to the sacral segment changes the state of animals from light anesthesia to deep anesthesia, and that this change is mediated by GABAergic systems suppressing the activity of noradrenergic LC neurons.

Transient neurological adverse effects following low dose radiation therapy for early stage testicular seminoma.

BACKGROUND AND PURPOSE: The aim of this study was to estimate the rate of neurological adverse effects following radiotherapy for testicular seminoma and to disclose possible dose-related effects. PATIENTS AND METHODS: All seminoma patients (n=346) treated 1980-2001 at our department with radiotherapy as the only treatment modality following orchiectomy constitute the study group (median follow-up 10 years). Since 1980, clinical data including possible side effects have systematically been recorded in these patients. These records were used to identify men with possible neurological adverse effects. Univariate logistic regression was used to estimate dose-related effects. RESULTS: Overall, 11 men (3.2%) with neurological symptoms probably related to radiotherapy were identified. Seven men treated with 25.2-36 Gray presented with sensory symptoms about 2 months following radiotherapy. These symptoms resolved in all but one after 1-3 months. The remaining four men (dose 36-40 Gray) had motor impairment which lasted at least one year, but none had persistent pareses at long-term follow-up. There was a statistically significant (p=0.02) increase in rate of motor symptoms with higher dose. CONCLUSIONS: Although motor impairment is unlikely to occur at current standard doses for seminomas, physicians should be ware of the sensory symptoms these men may exhibit.

Neurophysiological studies in malignant disease with particular reference to involvement of peripheral nerves.

Neurological and neuromuscular disorders are frequent complications in patients with neoplasms and may involve the neuromuscular system, including motor and sensory nerve cell bodies, axons, myelin, neuromuscular transmission and muscle alone or in combination. Electrophysiological studies are of value in delineating the type, degree and extent of involvement, and may be of assistance in pointing towards the underlying cause: paraneoplastic factors, treatment with chemotherapy or radiation or metastatic infiltration. Though some electrophysiological features may be characteristic of certain syndromes, they rarely can stand alone but require clinical, pathological, radiological, and laboratory studies to obtain a diagnosis. Even in cases where such studies are obtained, a final diagnosis may only be ascertained during follow up, since the neuromuscular disorders frequently occur before the neoplasm is detected.

[Peripheral neuropathy in cancer]. / Perifer nevropati ved kreft.

Neuropathy is a quite common finding in cancer patients. If the cancer is known, the main clinical problem is often whether the symptoms and signs are caused by metastasis or recurrence, or if the neuropathy can be related to effects of the oncological treatment. In addition to the clinical findings, radiological and neurophysiological examination can often be of considerable diagnostic help. Peripheral neuropathy may also be the first manifestation of the cancer, as in paraneoplastic neuropathies. Detecting the tumor in these cases may improve the oncological prognosis, as the neuropathy often precedes tumor symptoms by several years. A determined approach in searching for an occult cancer is necessary. The neuropathic symptoms are seldom life-threatening. However, the neuropathy may cause distressing symptoms, and symptomatic treatment and rehabilitation is often required.

Hyperbaric oxygen corrects sacral plexopathy due to osteoradionecrosis appearing 15 years after pelvic irradiation.

In 1982, a 55-year-old woman was treated by total cystectomy and adjuvant radiotherapy/chemotherapy for a leiomyosarcoma of the bladder. Fifteen years later she presented with symptoms and signs of sacral plexopathy. Investigations revealed osteoradionecrosis of the sacrum. Hyperbaric oxygen therapy (HBO2) was instituted and progressive resolution of the neurological complaints followed. HBO2 should be considered when managing late-onset sequelae in previously irradiated patients.

Fecal incontinence after pelvic radiotherapy: evidences for a lumbosacral plexopathy. Report of a case.

PURPOSE: Clinical manifestations of radiation-induced lumbosacral plexopathy remain a rare event. We report the case of a 62-year-old woman with neurogenic fecal incontinence that occurred after radiotherapy of cervical carcinoma. METHODS: Anorectal, bladder, and lower limb sensory-motor functions, as biologic and morphologic explorations, were performed on repeated occasions. RESULTS: Anorectal manometry, conduction times of pudendal nerves, sacral latencies, and pudendal nerve-evoked corticals disclosed lesions of the lumbosacral plexus that was confirmed by bladder manometry and electromyography of lower limbs. Biologic and morphologic explorations were within normal ranges. CONCLUSION: Because no other cause except radiation was demonstrated in this case, we suggest that plexopathy may be a late-occurring complication of radiotherapy.

Acute lumbosacral plexopathy during and after preoperative radiotherapy of rectal adenocarcinoma.

The benefit of preoperative radiotherapy of adenocarcinoma of the rectum with respect to a reduced local recurrence rate and an improved survival should be weighed against adverse effects. For 14 years a three-beam, isocentric technique was employed at our hospital to deliver five fractions (5.0 or 5.1 Gy), over 5 or 7 days preoperatively, to patients with rectal cancer which was considered primarily resectable. The adverse effects of the radiotherapy were few, but acute pain and subacute neurological symptoms and signs did occur. An apparent increase in the frequency of these symptoms/signs was noted during 1993. The pain and neurological symptoms are described in case reports and the individual treatments are reviewed. The three-beam technique was analyzed in detail with individual, CT-based, three-dimensional dose-planning and dose distributions in the vicinity of the lumbar nerve plexus are presented. The major result of this analysis showed that technical errors could be excluded, that human errors were unlikely, and that the culprit probably was an unexpected sensitivity to marginal changes in the daily dose and unknown or unexpected radiosensitizing effects of concurrent diseases or medication.

Radiation induced lumbosacral plexopathy in gynecologic tumors: clinical findings and dosimetric analysis.

PURPOSE: Radiation-induced lumbosacral plexopathy is a rare complication of pelvic irradiation. METHODS AND MATERIALS: We report four cases among 2,410 patients treated to the pelvis for carcinoma of the cervix and carcinoma of the endometrium. All patients received both external beam and intracavitary radiation. The total calculated dose to the lumbosacral plexus was on the order of 7300 cGy. RESULTS: All 4 cases presented developed lumbosacral plexopathy. CONCLUSIONS: Although a few permanent lumbosacral lesions have been reported for patients treated with conventionally fractionated external beam, this syndrome is more often seen in patients treated with intracavitary irradiation for cervical or endometrial carcinoma.

Palliative-radiotherapy in lumbosacral carcinomatous neuropathy.

The authors report their own experience in obtaining pain relief in 13 recurrent or disseminated cancer patients affected by lumbosacral carcinomatous neuropathy (LCN). The site, where the disease involved the lumbosacral plexus or its branches, was palliatively irradiated with a few large fractions. The average duration of response was 196 days. Median survival (uncensored) was 185 days (range 47-636 days).